Study of the relations of sink and source in saffron by means of correlation coefficients under different irrigation and fertilization levels

Saffron is the main medicinal plant of Iran. In order to study the relations of sink and source between saffron leaves and corms, a split plot experiment was conducted on the basis of complete randomized block design with three replications in a field in the Ashkezar city of Yazd province during 2013-2014. The main plots and sub plots were irrigated with three levels (100%, 75% and 50% of ETc) and the fertilization management methods including control (without any fertilizer or manure), applying 10 t/ha cow manure, 10 t/ha vermicompost by spreading, 10 t/ha vermicompost buried under planting corm rows, 5 t/ha vermicompost buried under planting corm rows, or spraying 10 l/ha Humaster Saffron fertilizer for 1 or 2 times after flowering. The Pearson correlation coefficients were calculated between leaf length in every measuring stage and the weight of biggest corm at the end of the first year (as daughter corm). The results showed that correlation coefficients were decreased until 40 days after emergence and then increased. The highest correlation coefficient reached around 80 days after emergence and followed until the end of the growth period. The best corm yield was reached for 10 t/ha vermicompost buried under planting corm rows. Also under different irrigation regimes, the best results were obtained through full irrigation treatment.